Contendered nonwoven/pulp composite fabric and method for making the same

ABSTRACT

The present invention is directed to a nonwoven fabric made from a composite of nonwoven and pulp where the nonwoven has a high loft derived from a heat set three-dimensional relief structure and/or hydroengorged fiber structure. A nonwoven web is hydraulically treated to create a hydroengorged material having an increased loft. Alternatively a nonwoven web is treated to have a heat set three-dimensional relief structure. The treated web is then hydroentangled with pulp to form a cotendered nonwoven/pulp composite fabric.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims is a U.S. national phase of PCT Application No.PCT/US2007/008794, filed Apr. 10, 2007, which claims priority to U.S.Provisional Application No. 60/791,010, filed Apr. 10, 2006.

FIELD

The present invention relates to nonwoven/pulp composites. Morespecifically, the present invention relates to spunbond and pulpcomposites having a high loft.

BACKGROUND

Composite nonwoven/pulp fabrics have been used for applications where astable and fixed absorbent structure is required. The pulp providesabsorbency and the network of fibers in the nonwoven provides astructure for retaining the pulp and significantly increasing the wetstrength of the material. One use for these fabrics is as a wipe,particularly a wipe that is impregnated with a solution duringmanufacture and before use.

Composite nonwoven/pulp fabrics are conventionally made by depositing apulp layer on top of a nonwoven web and subsequently hydroentangling thenonwoven and pulp together. The composite may also include a secondnonwoven web that is placed on top of the pulp and is alsohydroentangled.

In the past, it has not been possible to obtain a spunbond/pulp wipehaving the softness and drapability of wipes made from viscose or aviscose blend. The present invention achieves a softness and drapabilitycomparable to viscose wipes using a spunbond/pulp composite. The presentinvention has a further benefit in that the continuous fibers of thespunbond nonwoven provide considerably greater wet strength than wipesmade with carded staple cellulosic fibers, particularly in the CDdirection.

It is desirable for wipes to have a high loft, corresponding to improvedsoftness. A recent improvement for enhancing the loft of nonwoven websis the use of a hydroengorgement process. Hydroengorging is a process bywhich a nonwoven web, having been first thermally or ultrasonicallybonded, is subsequently tenderized with water jets to improve the loftof the web while still retaining most of its distinct bond sites andconsequently its original strength. Some fibers may be extricated fromtheir bond sites resulting in increased thickness or caliper and insignificant improvement in softness, hand and touch. During thehydroengorgement process, the fibers in the regions between bond sitesare forced to move out of the flat plane of the original nonwoven andconsequently the regions between bonds fluff up and gain loft andsoftness. The bulked structure thus produced has larger voids betweenbonds compared to the original nonwoven structure, as indicated by anincrease in air permeability of the new structure by at least 15%compared to the original nonwovens structure. This hydroengorgementprocess is further detailed in U.S. Patent Application Publication No.2006-0057921 A1, filed Sep. 10, 2004, which is hereby incorporated byreference.

An aspect of the present invention is to improve the loft and feel ofspunbond/pulp composites by using hydroengorged spunbond webs. Theimproved loft provided by the hydroengorgement process allows for aspunbond/pulp composite that is comparable to a viscose wipe in softnessand drapability and has an improved wet strength in both the machine andcross directions due to its use of spunbond fibers.

It is also desirable in particular applications to provide a nonwovenhaving a three-dimensional relief structure. Particular types ofthree-dimensional relief surfaces include regularly creped, irregularlycreped, such as might be made by the MICREX process, and various regularpatterns such as a waffle structure (such as might be made by a pair ofheated rolls, one having male projections and the other having matingfemale depressions) or a bowl/cup structure (such as might be made by apair of heated rolls, one having cup-like projections and the otherhaving mating-bowl-like recesses). The waffle-like structure may also bereferred to as “pyramids” and the bowl/cup design may be referred to as“cones.”

While composites of carded nonwoven and pulp have been made usinghydroentanglement and a three-dimensional forming surface to rearrangethe fibers therein to produce the desired relief surface, this does notwork well with composites of spunbond nonwoven and pulp. The differenceis that, while the short staple fibers of the carded nonwoven are easilyrearranged by hydroentanglement to assume the relief structure of athree-dimensional forming surface, the continuous fibers of a spunbondnonwoven will return substantially to their original, flattened state assoon as the composite is subjected to any tension, heat and/or pressure(for example the winding used to produce a roll of composite material).This is because the continuous fibers of a spunbond web are not free torearrange themselves to conform to the forming surface. Further, whenthe composite is passed through the drying unit under tension (to dry itafter hydraulic treatment), the elevated temperatures encounteredtherein may return the composite to its original flattened state.

Once pulp has been added to the nonwoven web or webs to form thecomposite fabric of spunbond and pulp, it is also generally undesirableto provide the entire composite with a three-dimensional reliefstructure (for example, by creping) because the additional mechanicalstress may cause disintegration of the fabric structure and/or anuneconomical loss of pulp from the composite fabric.

An aspect of the present invention overcomes the aforementioned problemsin forming a spunbond/pulp composite with a three-dimensional reliefstructure by creating a heat set three-dimensional relief structure inthe spunbond nonwoven prior to formation and hydroentanglement of thecomposite.

The hydraulically co-entangled combination of a nonwoven having ahydroengorged or three-dimensional heat set structure with one or moreother components (i.e. pulp) results in a cotendered nonwoven structurethat is both bulky and soft.

SUMMARY OF THE INVENTION

An exemplary object of the present invention is a composite fabricformed from at least one nonwoven web comprising continuous fibers andpulp. The nonwoven web comprising continuous fibers is hydroengorged toimprove its loft and the composite fabric including the hydroengorgedweb and pulp are hydraulically treated to intertwine the continuousfibers and pulp.

In a variation of the present invention at least two nonwoven webscomprising continuous fibers are hydroengorged and formed into acomposite fabric.

In a variation of the present invention at least one nonwoven web ismade from spunbond fibers.

In another variation of the present invention, the composite fabricincludes two webs that have been hydroengorged and subsequentlycalendered or ultrasonically bonded with a superposing pattern prior tobeing hydroentangled with a pulp layer.

In an additional variation of the present invention, the nonwoven websof the composite fabric are bonded with a bonding pattern that includesa graphic design.

In another variation of the present invention, the nonwoven webs of thecomposite fabric are ultrasonically embossed with a graphic design.

Another aspect of the present invention is a composite fabric formedfrom at least one web, comprising continuous fibers, that has been heatset so as to have a three-dimensional relief structure. The treated weband pulp are subsequently hydraulically treated to intertwine thecontinuous fibers and pulp.

In an additional variation of the present invention, the compositefabric including a hydroengorged web or web having a heat setthree-dimensional relief structure includes a color graphic design.

In another variation of the present invention, a partially debondednonwoven web or initially unbonded hydraulically treated web ofcontinuous fibers is hydroentangled with pulp to form a compositefabric.

Another exemplary object of the present invention is a method forforming high loft fabric having the steps of forming a nonwoven webcomprising substantially of continuous fibers and subsequently deformingthe nonwoven web to create a three-dimensional relief structure at atemperature sufficiently high enough that the three-dimensional reliefstructure is resistant to subsequent processing steps.

An exemplary object of the present invention is a method formanufacturing a composite fabric formed from at least one hydroengorgedweb and a pulp layer where the hydroengorged web and pulp arehydroentangled.

Another exemplary object of the present invention is a wipe formed froma composite fabric formed from at least one nonwoven web comprisingcontinuous fibers and pulp. The web comprising continuous fibers istreated to improve its loft and the composite fabric including thetreated web and pulp are hydraulically treated to intertwine thecontinuous fibers and pulp.

An exemplary object of the present invention is an absorbent articlecontaining a composite fabric formed from at least one nonwoven webcomprising continuous fibers and pulp. The web comprising continuousfibers is treated to improve its loft and the composite fabric includingthe treated web and pulp are hydraulically treated to intertwine thecontinuous fibers and pulp.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and related objects, features and advantages of the presentinvention will be more fully understood by reference to the followingdetailed description of the presently preferred, albeit illustrative,embodiments of the present invention when taken in conjunction with theaccompanying drawing wherein:

FIGS. 1 and 2 are schematic isometric views, partially in section, of anonwoven web, before and after hydroengorgement, respectively;

FIGS. 3 and 4 are fragmentary top plan views of an engraved bonding rollhaving elliptical or oval bonding points (to an enlarged scale) and theresultant fabric produced thereby (to a reduced scale), respectively;

FIG. 5 is a schematic side plan view, partially in section, of anonwoven web, having a heat set three-dimensional relief structure, andpulp deposited thereon;

FIGS. 6A-6C are schematic isometric views, partially in section, of anonwoven web, having a heat set three-dimensional relief structure;

FIG. 7 is schematic representation of a process used in hydroengorging aweb of substantially continuous fibers;

FIG. 8 is schematic representation of a process used in treating a webof substantially continuous fibers to form a heat set three-dimensionalrelief structure;

FIG. 9 is schematic representation of a process used in forming ahydroentangled composite fabric.

FIGS. 10A and 10B are schematic representation of cold needlingprocesses.

DETAILED DESCRIPTION

The present invention is a composite fabric having one or more nonwovenwebs hydroentangled with a layer of pulp, wherein the nonwoven webs havebeen treated to have an improved loft. Preferably the nonwoven web orwebs are made from continuous fibers. More preferably, these continuousfibers are meltspun fibers which can be further characterized asspunbond or meltblown fibers based on the diameter of the fibers and theproperties of the nonwovens that are formed from the fibers. For thepurposes of this disclosure, “spunbond fibers” refers to continuousfibers having an average fiber diameter greater than 8 microns whereas“meltblown fibers” refers to continuous fibers having an average fiberdiameter less than 8 microns, regardless of the process used tomanufacture the fibers. The nonwoven webs may be formed from multiplelayers of fibers, for example a spunbond-meltblown-spunbond or SMS web.The composite fabric may also have a reinforcing layer such as a scrim.Composites having one or more nonwoven webs made from carded fibers mayalso be used.

The fibers making up the nonwoven webs of the present invention are notlimited to a particular material. For example, the fibers can be madefrom polyolefins such as polypropylene and polyethylene or polyester,polylactic acid (PLA), polyamide or cellulosic fibers and combinationsthereof in bicomponent or multicomponent fibers. Preferably, the fibersare made from polypropylene or polyester. Bicomponent and multicomponentfibers may be used as may fibers with circular or noncircular polygonalcross sections. Splittable fibers, typically multicomponent fibers mayalso be used.

An advantage of using bicomponent or multicomponent fibers is thatimproved bonding between the fibers and improved adhesion to the pulpcan be obtained. This results in increased strength in the finalcomposite without sacrificing softness or bulk.

An advantage of using fibers with a non circular polygonal cross sectionis that the fiber surfaces can act as an improved filter during thehydroentanglement process and prevent pulp from washing out of thecomposite. Further, fiber to fiber friction is increased resulting inimproved strength without sacrificing softness or bulk.

As discussed in the context of the present invention, pulp can be woodpulp fibers, but also includes other materials having similar absorbentproperties. The pulp may be added in either an air-laid, wet-laid ortissue feeding process. For example, cotton linters or tissue could beused instead of or blended with wood pulp fibers. Synthetic materialssuch as viscose fibers may also be used alone or in a blend. The pulpmay also contain polymeric or binder fibers and may contain SAP or otherabsorbent particulates. The use of a particular pulp material willdepend on the intended use of the finished product.

Preferably, the composite fabric of the present invention includes atleast one spunbond web. Composites combining only one spunbond web and apulp layer are generally called SP fabrics whereas composites withspunbond webs on either side of a pulp layer are called SPS fabrics. Thecomposite fabric of the present invention may also contain additionalnonwoven webs or pulp layers and is not intended to be limited to theconfigurations described above. For example, an SMS or meltblown web maybe used instead of a spunbond web. In addition, if more than onenonwoven web is used, some or all of the additional webs may not betreated to have an improved loft.

In a preferred embodiment of the invention, a hydroengorged spunbond webis used as an outer surface for a spunbond/pulp composite. In a firststep, a spunbond web is hydroengorged, preferably to effect an increaseof at least 50% in caliper and an increase in air permeability of atleast 15%. Preferably, a layer of pulp is then air laid on top of thehydroengorged spunbond. Additional nonwoven webs, preferably one or morespunbond webs, may optionally be added to the pulp layer. If additionalnonwoven webs are used, the nonwoven webs may also be hydroengorged. Thecomposite is then hydroentangled to mix the pulp into the fiber matrixof the nonwoven webs.

A benefit of using hydroengorged spunbond webs is that the resultingfabric has an improved softness, appearance, bulk thickness and drape,both when dry and when wet. Additionally, the improved loft of thehydroengorged spunbond aids in retaining a greater amount of pulp duringthe coentanglement step. FIGS. 1 and 2 show cross-sections representinga nonwoven web before and after hydroengorgement.

An alternative method for altering the surface properties of ahydroengorged web is the use of a modified screen during thehydroengorgement process. Typically, a hydroengorgement forming surfacecan be a drum or belt comprising a fine mesh screen for supporting anonwoven web. This screen allows water from the water jets of thehydroengorgement machine to pass into the hydroengorgement formingsurface relatively uniformly over the surface of the nonwoven web. If athicker and more spaced apart mesh is used, water from thehydroengorgement jets will be directed into the empty areas of the mesh.As a result, the fibers of the web will be consolidated around theseempty areas and the resulting web may have a variable density and theappearance of having apertures. It is also possible to add graphicalelements to the hydroengorged web by adding of wire elements in theshape of the desired graphic to the screen mesh. By using a thicker wirefor the graphic elements than is used in the rest of the mesh, it isbelieved that the fibers of the web can be distributed to create agraphic element.

Another embodiment of the present invention is nonwoven/pulp compositeusing a nonwoven having frangible bonds or no bonding whatsoever. Bothof these types of nonwovens have an improved loft although theysacrifice strength in the process. A frangibly bonded nonwoven is anonwoven that is bonded such that during hydraulic treatment asubstantial number of bond points become completely debonded. U.S. Pat.No. 6,321,425, hereby incorporated by reference, describes such anonwoven. U.S. Pat. No. 6,903,034 hereby incorporated by reference,describes an initially unbonded but hydraulically treated nonwovenformed from continuous fibers. In this nonwoven, the continuous fibersare entwined such that they act as bonds and provide strength to thematerial.

The nonwoven/pulp composite of the present invention may be embossedprior to the step of hydroentangling the pulp and nonwoven web or webs.A particular advantage of this process is that a pattern or a graphicaldesign may be embossed or imprinted by softening or melting the fibersof the nonwoven. Exemplary graphic designs are animals or flowers.During the subsequent hydroentanglement process the bonded regions willact to reflect the water jets, thus pushing pulp away from the bondedregions. This process results in a clearly visible pattern that isenhanced by the lack of pulp and avoids the need for any subsequentembossing step.

In an embodiment of the present invention, each nonwoven web isinitially thermally bonded with a pattern, preferably a cellularpattern, prior to being hydroengorged. The use of a cellular pattern hasbeen found to be particularly beneficial because during thehydroentanglement process the pulp is pushed into the open areas of thepattern resulting in a softer, loftier fabric. Although thermal bondingis the preferred method of bonding, any commonly known bonding method,for example ultrasonic bonding, may be used.

Commonly owned U.S. Pat. Nos. 6,537,644, 6,610,390, and 6,872,274, eachof which is incorporated herein by reference, disclose nonwovens havinga non-symmetrical pattern of fusion bonds (that is, an anisotropic orasymmetrical pattern). As disclosed in these patents, bonds in anasymmetrical pattern may have a common orientation and commondimensions, yet define a total bond area along one direction (e.g., theMD) greater than along another direction (e.g., the CD) which isoriented orthogonally to the first direction, such that the points forma uniform pattern of bond density in one direction different from theuniform pattern of bond density in the other direction. Alternatively,as also disclosed in these patents, the bonds themselves may havevarying orientations or varying dimensions, thereby to form a pattern ofbond density which differs along the two directions. The bonds may besimple fusion bonds or closed figures elongated in one direction. Thebonds may be closed figures elongated in one direction and selected fromthe group consisting of closed figures (a) oriented in parallel alongthe one direction axis, (b) oriented transverse to adjacent closedfigures along the one direction axis, and (c) oriented sets withproximate closed figures so as to form there between a closedconfiguration elongated along the one direction axis. A preferredpattern is the PILLOW BOND pattern shown in FIGS. 3 and 4. In FIG. 3shows an enlarged scale view of bonding points 120 of the engraving orpatterning rolls 110, whereas FIG. 4 shows a relatively reduced scaleview of the patterned fabric 110 produced thereby. In both figures, thebonding points 120 form a larger closed FIG. 100.

In an embodiment of the invention, each nonwoven web is bonded with botha bonding pattern and a graphic design. This may be achieved by using anengraved bonding roll with the graphic design superimposed on thebonding pattern or through an ultrasonic process. Alternatively, twostages, for example a bonding roll and an ultrasonic process may beused. Unlike the bonding pattern, the graphic design serves a primarilyornamental function and may depict animals, plants or geometric figuresand these graphic elements are greater in size than the base units of atypical bonding pattern. Generally, the graphic elements of the graphicdesign will extend over an area larger than 0.25 square centimeters asthe greater size makes the graphic elements more discernible.

A cellular superposing pattern may also be used to post emboss thenonwoven/pulp composite. The pattern may be formed by two heated bondrolls comprising one smooth roll and one roll engraved with the pattern.Alternatively, an ultrasonic process using the same pattern anvil rollmay be used. The cellular pattern may be combined with a graphic designor may stand alone. If the pattern is combined with a graphic design,the lines of the graphic design should be slightly thicker in order toimprove the visibility of the graphic design. The advantage of using aclosed pattern for calendering is that the superposing pattern will bein register on the nonwoven layers and thus encapsulate the pulp andbond the layers of the composite structure to prevent delamination.

In a preferred embodiment, the nonwoven/pulp composite fabric isstructured so that when folded upon itself the adjacent exteriorsurfaces of the composite fabric do not slide on one another. Thisoccurs because the relief patterns of the surfaces are at leastpartially complementary, i.e. the raised portions of one surface willfit into the depressed portions of the other surface. This configurationis sometimes described as tongue and groove. Accordingly, there is anincrease in the common surface area between the two surfaces and acorresponding increase in surface friction. The benefit of this propertyis seen in application such as wipes where the user may fold the wipefor improved comfort. The anti-slip properties of the fabric may also beenhanced by using splittable fibers or microfibers for the anti-slipsurface.

The relief pattern of the nonwoven/pulp composite fabric preferably hasa average peak thickness of between 1.1 and 2 times of the averageminimum thickness of the fabric. More preferably,

In an alternate embodiment of the present invention, a heat setthree-dimensional relief structure is applied to a nonwoven web,preferably spunbond. A layer of pulp and, optionally, another nonwovenweb are then applied to the heat set three-dimensional relief nonwovenweb and all of the layers are hydroentangled to form a composite fabric.

The present invention encompasses any method of creating a heat setthree-dimensional relief structure on one or both of the individual websprior to hydroentanglement or formation into a composite. A heat settingtechnique such as creping, microcreping (an example of which can befound in U.S. Pat. No. 4,921,643) or waffling may be used to create thethree-dimensional relief pattern. Heat setting “resets” the memory ofthe continuous fibers of the spunbond into a desired pattern.

The temperature for heat setting is dependent on the polymer to be used.Typically, the heat setting is performed at temperatures of at least60-120° C. More specifically, the heat set temperature should be atleast 10 degrees higher than the temperature conventionally used for thedrying unit, for example about 100-110° C. for polypropylene spunbond.

The three-dimensional relief structure of the present invention ispreferably created after the nonwoven web is formed and bonded. If therelief structure is created during web formation or before heatedcalender bonding, any relief structure thus created will tend to flattenwhen the web is subsequently passed through a heated roll nip of athermal bonding calender.

Once the three-dimensional relief structure is created the nonwoven webis then preferably hydroengorged to soften it and create further loft.Pulp is then deposited, for example air laid or wet laid fed, onto theweb. A second nonwoven web with three-dimensional relief may be placedon top of the pulp layer. The composite is then hydroentangled. Thehydroentangled composite is then de-watered and passed through an airdryer. The heat setting thus provides increased loft to the nonwovenweb, and the subsequent hydroengorgement thereof provides increasedsoftness and flexibility.

A benefit of the three-dimensional relief structure is that the pulpreinforces the relief structure. A representation of this feature isshown in FIG. 5. As shown, a pulp layer 22 fills the voids of the reliefstructure of a nonwoven web 6 and provides additional resiliency towardsdeformation or flattening of the three-dimensional relief structure.

The three-dimensional relief structure thus created is preferably atleast three times greater in caliper than the caliper of the precursorweb. Preferably the three-dimensional relief structure consists ofgrooves, valleys, cups, bowls, etc. (with the relief structure topvisible from one surface of the web and the relief structure bottomvisible from the other side of the web) as opposed to mere surfaceimpressions which would be visible on only one side of the web. Someexamples of three-dimensional relief structures are shown in FIGS. 6A-C,namely, an irregular relief surface, a bowl relief surface and a pyramidrelief surface.

The total caliper and bulk generated is a combination of (a) thethree-dimensional relief structure created by the heat setting processand/or (b) any bulking created by the hydroengorging the webs prior toformation of the composite, and (c) the bulking created byhydroentanglement the composite fabric.

Note that, while a nonwoven web with a heat set three-dimensional reliefstructure may be hydroengorged prior to being formed into a composite,this hydroengorgement step on the individual nonwovens is not critical.The increased loft and softness of the present invention are obtained(albeit perhaps to a lesser degree) when the only hydraulic treatment isperformed after formation of the composite, i.e., to integrate thecomposite by water needling and not on the individual pre-compositenonwoven webs.

An embodiment of the process invention is shown in FIG. 7. First,spinning beams 2 and 4 are used to form a nonwoven web 6 on conveyorbelt 8. The web 6 is then bonded with calender rolls 10 and 12. The web6 is then hydroengorged at a hydraulic treatment station 14.

In another embodiment, shown in FIG. 8, instead of undergoing hydraulictreatment, a nonwoven web 6 is passed through a pair of heated,patterned rolls 18 and 20. The rolls 18 and 20 have complementary reliefpatterns, i.e. a protrusion on one roll will be aligned with anindentation on the other roll. The rolls 18 and 20 are preferably heatedto between about 60° C. and 120° C. In a preferred embodiment usingpolypropylene fibers, the rolls 18 and 20 are heated to about 100-110°C. Alternatively, the nonwoven web 6 may be creped to create anirregular relief pattern.

In an embodiment of the present invention, shown in FIG. 9, thehydroengorged or patterned web 6 may be treated with a finish at afinishing station 14 to render it softer and more condrapable, such afinish being disclosed in U.S. Pat. No. 6,632,385, which is herebyincorporated by reference, or to modify the surface energy thereof andthereby render it either hydrophobic or more hydrophobic or hydrophilicor more hydrophilic. In the case of polypropylene fibers, which arenaturally hydrophobic, a hydrophilic treatment can prevent an adverseeffect on the absorbency of the pulp in the finished wipe. This stagemay take place prior to or after pulp deposition.

One embodiment of the present invention is an apertured cotenderednonwoven. Specifically, the cotendered nonwoven fabric of the presentinvention may be apertured using conventional methods to improvebreathability and fluid permeability. It is not necessary for thecotendered nonwoven to be fully apertured, for example one end of theapertures may remain closed. Generally, apertures are formed through aneedling process, usually with heated needles. Hot needles can melt orcause shrinkage in the fibrous material they come in contact with thusforming a clean opening in an aperture. Such openings are not alwayspreferred, particularly as molten or conglomerated fibrous material canincrease surface roughness and lead to skin irritation. By using coldneedles surface roughness can be greatly reduced. Although the aperturesformed through cold needling will have the general appearance of aregular aperture, the surface of the nonwoven through which the needlepasses may retain some fibers.

Two possible cold needling processes are shown in FIGS. 10A and 10B. InFIG. 11A the fibers of the nonwoven web 6 are pinched between a needle60 and the edge of a receiving hole 62 thereby cutting the fibers andforming a relatively clean opening for the aperture. In FIG. 10B, thereceiving hole 61 has a curved surface that prevents the fibers of thenonwoven from being cut. As a result the apertured nonwoven of FIG. 10Bis has an aperture that is closed at one end.

In a pulp deposition stage, a layer of pulp 22 is deposited on thenonwoven web 6. Preferably, the pulp 22 is air-laid although a wet-laidor tissue feeding process may be used instead. A second nonwoven web 24is deposited on top of the pulp 22. Preferably, this second nonwoven web24 has also been treated in the same manner as the first nonwoven web 6.

Prior to being hydroentangled, the composite fabric 32 may be passedthrough a set of rolls 26 and 28 for forming a pattern. Preferably, thispattern is a graphic design, for example flowers. The composite fabricis then passed through a hydroentanglement station 30 which interlocksthe fibers of the nonwoven webs 6 and 24 and the pulp 22 to form acotendered composite fabric 32. The lines of the pattern formed prior tohydroentanglement can act to reflect the water jets of thehydroentanglement station 30, thus pushing pulp away from the lines andreinforcing the pattern.

After the hydroentanglement step, the cotendered composite fabric 32 isdried in a through-air dryer 34. The composite fabric may then be bondedat a bonding station 36 in order to prevent delamination. Preferably,ultrasonic bonding is used as opposed to thermal bonding as the heat ofthe bonding rolls can cause the composite fabric 32 to shrink. Anunheated calender may be used as well. Preferably, a relatively largebond pattern is used such that the finished composite fabric 32 appearsembossed. A preferable pattern is a grid pattern. In a composite fabrichaving only one nonwoven web, the bonding may be applied to either thepulp or nonwoven side of the composite fabric 32. Finally, the compositefabric 32 is wound into rolls on winder 38.

In a preferred embodiment, the composite fabric 32 of the presentinvention includes a color graphic. The color graphic may be applieddirectly to the composite fabric 32.

As a final processing step, the composite fabric of the presentinvention may be impregnated with a lotion or cleaning fluid. Theimproved loft of the composite fabric 32 is believed to provide improvedretention capability for holding lotions and other fluids.

The cotendered composite fabric of the present invention is improvedover other composite fabrics in that it has a greater loft and improvedstrength in both the machine and cross directions. Further, the presentinvention produces less lint than composite fabrics having athree-dimensional relief structure that are made using carded staplefibers instead of spunbond. Another benefit of the present invention isthat the three-dimensional structure of the composite fabric reduces thesurface area of the fabric that comes into contact with a user'sfingers, thus providing an improved sense of dryness.

The cotendered composite fabrics of the present invention are applicablein a variety of fields. One application is to use the composite fabricas a wipe, with variations as to the construction of the wipe dependingon if the desired usage is as a consumer (baby) wipe, household wipe orindustrial wipe. Typically, all of these wipes would use a compositefabric having a basis weight of around 40-90 gsm. Preferably, the wipeswould have an SP configuration, specifically, one spunbond webhydroentangled with pulp. Depending on the application, the wipes may betreated with cleaning solutions, fragrances, moisturizing lotions orother solutions. Household and industrial wipes may contain abrasivematerials or include an external abrasive layer such as coarse meltblownfibers. Splittable fibers or microfibers may be used in the wipes toprevent the outer surfaces of the wipes from slipping when folded overonto themselves.

The cotendered composite fabrics of the present invention may also beused as a component of absorbent articles. Specifically, the compositefabrics may be used as part of the absorbent core for an absorbentarticle or may be used as an acquisition distribution layer or partthereof. In these application, the composite fabrics would typicallyhave basis weight of about 20-70 gsm. Composite fabrics used in anabsorbent core may include SAP. This SAP would typically be mixed withthe pulp prior to formation of the composite fabric and could comprise0-100% of the total pulp composition by weight. Preferably, anacquisition distribution layer would be made from an SP compositefabric. An SP composite fabric, preferably with a basis weight of about20-70 gsm, could also be used for the absorbent core of a thin absorbentarticle such as a panty liner or sanitary napkin.

An application of the present invention is a nonwoven/pulp compositefabric for use as a printable backsheet for an absorbent article.Specifically, the pulp of the composite fabric provides a substratewhich can be printed whereas the nonwoven, preferably a hydroengorgedspunbond, provides a soft hand feel and strength.

Other applications of the present invention involve the use of anadditive with a nonwoven/pulp composite. An oil absorbent compound canbe added to improve the capacity for the composite fabric to absorb oil,for instance for use an industrial wipe. Likewise, a bleaching compoundcould be added for use in cleaning applications.

The cotendered composite fabrics of the present invention are alsosuitable for use as packaging. A sheet of composite fabric could be usedas absorbent packaging for food items such as meat. A composite fabriccould also be used as protective packaging as a replacement forprotective packaging made from an SMS fabric. Typically, the basisweight for these applications is about 30-90 gsm. An advantage of anonwoven/pulp composite fabric over an SMS fabric is that nonwoven/pulpcomposite provides more opacity. A more opaque material is moreaesthetically pleasing, especially when used as packaging for meat.

An application of the present invention is a composite nonwoven/pulpcomposite fabric for use in electronics packaging as a replacement forsilica gel. Silica gel is a desiccant used to prevent the build up ofmoisture. A nonwoven/pulp composite fabric could provide similarmoisture absorption for a lower cost.

The teachings of the present invention may also be applied tolightweight nonwovens having a basis weight of between 5-15 gsm and morepreferably about 11 gsm. At very low basis weights, structural integritybecomes an important consideration. A lightweight nonwoven/pulpcomposite can be made using a hydroengorged spunbond web in accordancewith the present invention. Specifically, because the hydroengorgedspunbond web combines both high strength and high loft, a low basisweight composite fabric will still retain its structural integrity.

Other applications which the composite fabrics of the present inventioncould be suitable for are filters, face masks, protective garments andmedical fabrics such as fenestration drapes. Additional applications,which are not mentioned herein, may also exist and the disclosure of theaforementioned applications is not intended to be inclusive of all thepotential applications.

Example 1

A layer of 15 gsm hydrophobic PP-Spunbond PB™ as supplied by FirstQuality Nonwovens, Hazleton, Pa., USA, was fed with a velocity of 30m/min onto a conveyor belt and transported through an airlaid unit asoffered under the tradename “Wingformer” by Celli, SA, Lucca, Italy.

With the Wingformer a layer of 30 gsm of a kraft fluff pulp that wasbleached without elemental chlorine available from Weyerhaeuser, NewBern, N.C., USA under the tradename “NB416 Kraft” was evenly spread onthe bottom layer spunbond.

The composite of the hydroengorged spunbond and the pulp was thenexposed to an hydroentanglement unit from Rieter Perfojet, Montbonnot,France and treated on the pulp surface side with 4 injectors usingpressure steps from 30 to 90 bar. During the final hydroentanglementstep, the composite was treated from the spunbond side using one beam at35 bar to push the pulp into the voids of a perforated drum sleevehaving rectangular holes with a dimension of 1×1.5 mm and a hole to holedistance of 3 mm in machine direction and a hole to hole distance of 2mm in machine cross direction to form a pulp surface with reliefprotrusions to increase the roughness and friction of that surface.

The wet composite was dried with an Through-Air-Dryer (from RieterPerfojet, Montbonnot, France) in a way that the spunbond side wasexposed to the surface of the drum of the dryer.

Prior to the manufacturing of the composite, the 15 gsm precursorspunbond had an caliper (INDA test method 120.1-92) average of 187microns. The dried composite had a basis weight of 45 gsm and a caliperaverage of 387 microns. The composite had an average absorption capacityof 8.3 g/g. Finally, the Handle-O-Meter (Thwing-Albert) softness gradewas in average of 42.3 g in the machine direction and 15.7 g in crossdirection.

Example 2

A composite fabric was made according to the process used in Example 1,however the 15 gsm PP-Spunbond PB™ nonwoven layer was firsthydroengorged pursuant to copending U.S. patent application Ser. No.10/938,079.

Prior to the manufacturing of the composite, the 15 gsm precursorhydroengorged spunbond had an caliper (INDA test method 120.1-92)average of 380 microns. The dried composite had a basis weight of 45 gsmand a caliper average of 640 microns. The composite had an averageabsorption capacity of 9.2 g/g. Finally, the Handle-O-Meter(Thwing-Albert) softness grade was in average of 36.4 g in the machinedirection and 11.9 g in the cross direction.

Example 3

A bottom layer of 11 gsm hydrophobic PP-Spunbond PB™ was fed with avelocity of 30 m/min onto a conveyor belt and transported through aWingformer airlaid unit. With the Wingformer, a layer of 33 gsm of NB416Kraft pulp was evenly spread on the bottom layer spunbond.

A second layer of 11 gsm hydrophobic PP-Spunbond PB™ was laid on top ofthe pulp layer to form a composite with a spunbond-pulp-spunbondstructure.

This three-layer-composite of spunbond and pulp was then exposed to anhydroentanglement unit from RieterPerfojet, Montbonnot, France andtreated on one surface side with 4 injectors using pressure steps from35 to 50 to 90 to 90 bar.

With an additional hydroentanglement step, the composite was treatedfrom the opposite spunbond side using one beam at 35 bar to push thepulp back into the voids of the first spunbond layer and further intothe openings of the drum sleeve of Example 1 to form a pulp-like-surfacewith relief protrusions to increase the roughness and friction of thatsurface.

The wet composite was dried with an Through-Air-Dryer (from RieterPerfojet, Montbonnot, France) in a way that the smooth spunbond surface,having substantially no pulp on the surface, was exposed to the surfaceof the drum of the dryer.

Prior to the manufacturing of the composite, the two 11 gsm precursorhydroengorged spunbond layers had an caliper (INDA test method 120.1-92)average of 127 and 134 microns. The dried composite had a basis weightof 55 gsm and a caliper average of 438 microns. The composite had anaverage absorption capacity of 6.1 g/g. Finally, the Handle-O-Meter(Thwing-Albert) softness grade was in average of 46.1 g in the machinedirection and 22.4 g in the cross direction.

Example 4

A composite fabric was made according to the process used in Example 3,however the 11 gsm PP-Spunbond PB™ nonwoven layers were firsthydroengorged pursuant to copending U.S. patent application Ser. No.10/938,079.

Prior to the manufacturing of the composite, the two 11 gsm precursorhydroengorged spunbond layers had an caliper (INDA test method 120.1-92)average of 234 and 238 microns. The dried composite had a basis weightof 55 gsm and a caliper average of 560 microns. The composite had anaverage absorption capacity of 6.4 g/g. Finally, the Handle-O-Meter(Thwing-Albert) softness grade was in average of 32.4 g in the machinedirection and 12.8 g in the cross direction.

Examples 1-4 demonstrate the advantages in terms of softness and bulk ofusing hydroengorged spunbond nonwovens to manufacture hydroentangledpulp composites. As hydroengorged spunbond nonwovens have an improvedbulk and softness compared to standard spunbond nonwovens and furthermaintain these properties during conversion to hydroentangled pulpcomposites. As such they are advantageous for use as the base substratesfor soft and bulky absorbent wipes/composites.

As the examples demonstrate, the composites structures can have a smoothsurface with substantially no pulp on that surface and a second roughand high-friction surface with substantially only pulp. The high pulpsurface can form a relief allowing the user to fold the wipe such thatthe rough surfaces of the folded wipe do not slip past each other, evenwhen wetted with a skin care lotion. Further, the smooth surface is softto the touch and can be used skin applications while the rough surfaceis used for cleaning coarse contaminated surfaces. One such dualapplication is a baby wipe where the smooth surface is used for thebaby's skin and the rough surface is used to clean messes on the baby'sclothing or surroundings.

We claim:
 1. A cotendered composite fabric comprising: a bonded firstnonwoven web comprising continuous fibers; and a first pulp layersubstantially comprised of pulp hydroentangled with the bonded firstnonwoven web; wherein, prior to being hydroentangled with the first pulplayer, said bonded first nonwoven web has a hydroengorged fiberstructure.
 2. The composite fabric of claim 1 wherein said firstnonwoven web has a basis weight of about 11-15 gsm.
 3. The compositefabric of claim 1 further comprising a reinforcing scrim.
 4. Thecomposite fabric of claim 1 wherein said composite fabric isultrasonically embossed.
 5. The composite fabric of claim 1 wherein saidcomposite fabric is embossed by a heated calender.
 6. The compositefabric of claim 1 wherein said composite fabric is embossed by anunheated calender.
 7. The composite fabric of claim 1 wherein saidcontinuous fibers comprise spunbond fibers.
 8. The composite fabric ofclaim 1 further comprising a second nonwoven web.
 9. The compositefabric of claim 8 wherein said composite fabric is ultrasonicallyembossed.
 10. The composite fabric of claim 8 wherein said secondnonwoven web comprises continuous fibers; and has one or more elementsselected from the group consisting of (a) a heat set three-dimensionalrelief structure; and (b) a hydroengorged fiber structure.
 11. Thecomposite fabric of claim 10 wherein said first and second nonwoven webshave a hydroengorged fiber structure.
 12. The composite fabric of claim10 wherein said first nonwoven web has a bonding pattern comprising agraphic design.
 13. The composite fabric of claim 10 wherein said firstand second nonwoven webs are calendered with a superposing pattern. 14.The composite fabric of claim 13 wherein said superposing patterncomprises a graphic design.
 15. The composite fabric of 14 wherein saidgraphic design comprises graphic elements having an average size greaterthan 0.25 square centimeters.
 16. The composite fabric of claim 10wherein said composite fabric comprises a color graphic design.
 17. Thecomposite fabric of 13 wherein said bonding pattern is anisotropic andbiased in the machine direction.
 18. A wipe comprising the compositefabric of claim
 1. 19. The wipe of claim 18 wherein said wipe is ahygienic wipe.
 20. The wipe of claim 18 wherein said wipe is anindustrial wipe.
 21. An absorbent article comprising the compositefabric of claim
 1. 22. The absorbent article of claim 21 wherein saidabsorbent article is a sanitary napkin.
 23. The absorbent article ofclaim 21 wherein said absorbent article is a diaper.
 24. The absorbentarticle of claim 21 comprising an acquisition distribution layercomprising said composite fabric.
 25. An absorbent sheet comprising thecomposite fabric of claim
 1. 26. The absorbent sheet of claim 25 whereinsaid absorbent sheet is a laminate of said composite fabric and at leastone nonwoven web.
 27. A fenestration drape comprising the compositefabric of claim
 1. 28. A garment comprising the composite fabric ofclaim
 1. 29. A desiccant comprising the composite fabric of claim
 1. 30.A method of manufacturing a composite fabric comprising the steps of:forming a first layer substantially comprised of continuous fibers;hydroengorging said first layer; depositing a second layer substantiallycomprised of pulp onto said first layer; and hydroentangling said firstand second layers.
 31. The method of claim 30 further comprising thesteps of: depositing a second layer substantially comprised of pulp ontosaid first layer; forming a third layer substantially comprised ofcontinuous fibers; and hydroentangling said first, second and thirdlayers.
 32. The method of 31 further comprising the step ofhydroengorging said third layer.
 33. The composite fabric of claim 1wherein said fabric comprises a first surface substantially free ofpulp.
 34. The composite fabric of claim 8 wherein said fabric comprisesa first surface substantially free of pulp.
 35. The composite fabric ofclaim 33 wherein said fabric comprises a second surface having a roughsurface profile.
 36. The composite fabric of claim 34 wherein saidfabric comprises a second surface having a rough surface profile. 37.The composite fabric of claim 35 wherein said second surface hasfeatures extending beyond the plane of said second surface wherein saidfeatures have a peak height of at least 20% of the caliper of saidcomposite fabric.
 38. The method of claim 30 further comprising the stepof: embossing said composite fabric using a cold calender.